Product Stories22 Aug 2019
If you want to weld geomembranes ranging from 0.5 millimeters to 2.5 millimeters thick quickly, easily and reliably, then you need at least one of LEISTER's brand new TWINNY T5 and TWINNY T7, automatic welding machines.

You may have wondered about the headline of this blog post, which sounds rather predictable. Ok, maybe so, but "plug in and weld" is the best way to put it in a nutshell. Anyone who has a TWINNY T5 or T7 in front of them for the first time can plug them in and start welding because both machines are so easy to operate. No matter if the user is a novice or professional, they're able to produce a perfect weld seam without much introduction or practice. 

Two performance classes: TWINNY T5 and T7 

The T5 and T7 performance classes have been developed by our engineers based around your specific needs. We'd like to thank you for providing feedback on a regular basis because your input has helped us raise the bar even higher and produce two, next-level machines. When we know what your needs are, we take them into account during the development of our new automatic welding machines. 

Choosing between TWINNY T5 or T7 will depend on your needs. 

If maintaining high performance welding with ultimate comfort is essential for you, then we recommend the well-rounded TWINNY T7. It comes equipped with a digital display showing the welding force and voltage, as well as connection to the myLeister app. Information about the myLeister app and the Leister Quality System (LQS) can be found here.

If you're looking for an easy-to-operate welding machine and don't need any modern digital functions, then the TWINNY T5 is the perfect solution for you. 

Differences between TWINNY T5 and T7 


  • Digital display for setting and monitoring speed, temperature and air flow range
  • Mechanical overload protection
  • Welding speed is almost 50% faster than the TWINNY T


  • Multifunctional display for setting and monitoring speed, temperature and air flow range
  • Voltage display 
  • Wireless connection, GPS, integrated LQS, connection to myLeister app
  • 100 % increase in welding speed over TWINNY T, with a brushless blower motor


Still having a hard time deciding between the two machines? Then continue reading for more detailed information that is sure to help you identify the right choice. 


Large travel rollers for more ground clearance on rough or uneven surfaces

Rough or uneven surfaces aren't ideal for welding geomembranes. Unfortunately, you usually can't choose the type of surface you're welding on; however, extra-large travel rollers have been developed for TWINNY T5 and T7. This gives you more ground clearance and reduces stress for these kinds of welding situations. 

Ergonomic design for effortless welding

The handles on TWINNY T5 and T7 are positioned on the housing so that both automatic welding machines are well balanced. This makes it easier for you to guide, move and transport. 


Also, to make sure that the handles fit your hand while working and transporting, they are made of a soft, non-slip material. 

Long life-span, easy to maintain and fast - even with undervoltage

Thanks to the stronger drive that consists of a motor, gearbox and chains, the TWINNY T5 and T7 are particularly durable and maintenance-friendly. Regardless of which of the two automatic welders you choose, you will enjoy either of them for long time, with low maintenance costs.

Additionally, the welding speeds have been greatly increased, thanks to the powerful blower and significantly higher heating output. In concrete terms, this means: TWINNY T5 is roughly 50% faster than its predecessor TWINNY T and TWINNY T7 is twice as fast, thanks to its brushless blower. 

Lastly, both the TWINNY T5 and T7 have high power reserves, eliminating damage due to undervoltage.


Digitally controlled and easy to operate

TWINNY T5 and T7 are digitally controlled and easy to operate, thanks to their intuitive display.

The TWINNY T7 has additional LQS including WiFi and GPS. Thus, all welding parameters are recorded in the T7. Simply download the myLeister app to your smartphone or tablet, add your TWINNY T7 and off you go. 

TWINNY T5 / T7: Equip yourself with the right machines to tackle your greatest challenges


  • Quick: Drive speed of 2.6 to 26 feet/minute
  • Powerful: 3300 watts, enabling more heating power
  • Intuitive: Easy-to-use display and user controls
  • Documented: TWINNY T7 records all welding parameters, thanks to LQS
  • Versatile: TWINNY T5 and T7 weld almost all plastic membranes from 0.5 - 2.5 mm or 20-100 mils
  • Dry and clean: The hot air dries moisture in no time at all, while dust and sand are blown away
  • Brushless blower motor: Significantly greater air flow range
  • Sustainable: TWINNY T5 and T7 are durable and easy to service